Bo Kyung Sohn

Background: Higher levels of physical activity (PA) have been linked to a reduced risk of Alzheimer's disease (AD) dementia among older adults. However, the mechanisms underlying the association between increased PA and a lower risk of AD‐related cognitive decline remain unclear. This study aimed to investigate the relationship between late‐life PA (PA _late ) and functional connectivity (FC) within major functional resting state brain networks in cognitively healthy older adults. Method: This study was part of the Korean Brain Aging Study for Early Diagnosis and Prediction of Alzheimer's Disease (KBASE). It included 157 cognitively normal (CN) participants who underwent comprehensive clinical assessments at baseline. The participants also received multimodal brain imaging including resting‐state functional MRI, structural MRI, [ ¹¹ C] Pittsburgh Compound B (PiB) positron emission tomography (PET), [ ¹⁸ F] fluorodeoxyglucose (FDG) PET, as well as an evaluation for PA _late . For major functional resting state networks (RSN) including the frontotemporal, default mode, dorsal attention, limbic, and salience (ventral attention) networks, within‐system FC was calculated as the median value of Fisher z‐transformed node‐to‐node functional connectivity within each network. Result: PA _late demonstrated a significant positive association with FC of the default mode network (beta = 0.216, p = 0.010). No significant associations were found in other networks. The association between PA _late and the default mode network FC remained significant even after controlling for AD imaging biomarkers, including global amyloid retention, AD signature region cerebral glucose metabolism, and AD signature region cortical thickness. Conclusion: These findings indicate that PA _late is associated with increased functional connectivity within the default mode network, independent of AD‐related brain pathologies. While further research is needed, these findings suggest a potential role in reducing the risk of AD and related cognitive decline.

Gihwan Byeon, Min Soo Byun, Dahyun Yi, Hyejin Ahn, Gijung Jung, Bo Kyung Sohn, Joon Hyung Jung, Yoon Young Chang, Kyungtae Kim, Hyeji Choi, Yoon Hee Kim, Yu Kyeong Kim, Koung Mi Kang, Chul-Ho Sohn, Dong Young Lee; for the KBASE Research Group. Clin Psychopharmacol Neurosci 2025;23:256-65. https://doi.org/10.9758/cpn.24.1238

이희건, et al. J Korean Neuropsychiatr Assoc. 2022 Aug;61(3):196-203. https://doi.org/10.4306/jknpa.2022.61.3.196

Background: Both physical activity (PA) and cognitive activity (CA) are known to reduce the risk of Alzheimer`s disease (AD) and related cognitive decline. However, pathophysiological mechanism underlying their protective effects for AD is still poorly understood. We aimed to investigate the moderation effects of current PA and CA on the relationship between amyloid‐beta (Aβ) and AD‐signature neurodegeneration in non‐demented older adults. Both physical activity (PA) and cognitive activity (CA) are known to reduce the risk of Alzheimer`s disease (AD) and related cognitive decline. However, pathophysiological mechanism underlying their protective effects for AD is still poorly understood. We aimed to investigate the moderation effects of current PA and CA on the relationship between amyloid‐beta (Aβ) and AD‐signature neurodegeneration in non‐demented older adults.Method: Two‐hundred sixty non‐demented (195 cognitively normal and 65 mild cognitive impairment) participants from the Korean Brain Aging Study for Early diagnosis and prediction of Alzheimer’s disease (KBASE) were included in this analysis. All participants underwent comprehensive clinical and neuropsychological assessment, [¹¹C]Pittsburgh Compound B (PiB) positron emission tomography (PET), [¹⁸F]fluorodeoxyglucose (FDG) PET, and magnetic resonance imaging. Using the multi‐modal brain imaging data, in vivo AD pathologies including Aβ deposition, AD‐signature region cerebral glucose metabolism (AD‐CM), and AD‐signature region cortical thickness (AD‐CT) were quantified. Current PA and CA were assessed using well‐validated questionnaires. General linear model analysis was conducted including AD‐CM (or AD‐CT) as a dependent variable and Aβ deposition, PA, CA, Aβ x PA interaction term, and Aβ x CA interaction term as independent variables.Result: We found significant Aβ x PA interaction effect on both AD‐CM and AD‐CT. Subgroup analyses showed that the inverse association between Aβ and AD‐CM (or AD‐CT) was weaker (i.e., smaller effect size) in higher PA group compared to that in lower PA group. In contrast, Aβ x CA interaction effect was not observed on neither AD‐CM nor AD‐CT.Conclusion: The findings suggest that current PA reduce AD‐type regional neurodegeneration induced by Aβ deposition, regardless of CA, in non‐demented older adults. When considered with PA, however, current CA appear not have any moderation effect on the relationship of Aβ deposition with the neurodegenerative change.

Objective: To assess the predictive ability of regional volume information provided by fully automated brain segmentation software for cerebral amyloid positivity in mild cognitive impairment (MCI). Methods: This study included 130 subjects with amnestic MCI who participated in the Korean brain aging study of early diagnosis and prediction of Alzheimer’s disease, an ongoing prospective cohort. All participants underwent comprehensive clinical assessment as well as ¹¹C-labeled Pittsburgh compound PET/MRI scans. The predictive ability of volumetric results provided by automated brain segmentation software was evaluated using binary logistic regression and receiver operating characteristic curve analysis. Results: Subjects were divided into two groups: one with Aβ deposition (58 subjects) and one without Aβ deposition (72 subjects). Among the varied volumetric information provided, the hippocampal volume percentage of intracranial volume (%HC/ICV), normative percentiles of hippocampal volume (HC_norm), and gray matter volume were associated with amyloid-β (Aβ) positivity (all P < 0.01). Multivariate analyses revealed that both %HC/ICV and HC_norm were independent significant predictors of Aβ positivity (all P < 0.001). In addition, prediction scores derived from %HC/ICV with age and HC_norm showed moderate accuracy in predicting Aβ positivity in MCI subjects (the areas under the curve: 0.739 and 0.723, respectively). Conclusion: Relative hippocampal volume measures provided by automated brain segmentation software can be useful for screening cerebral Aβ positivity in clinical practice for patients with amnestic MCI. The information may also help clinicians interpret structural MRI to predict outcomes and determine early intervention for delaying the progression to Alzheimer’s disease dementia.

An emerging body of literature has indicated that moderate alcohol intake may be protective against Alzheimer disease (AD) dementia. However, little information is available regarding whether moderate alcohol intake is related to reductions in amyloid-beta (Aβ) deposition, or is protective via amyloid-independent mechanisms in the living human brain. Here we examined the associations of moderate alcohol intake with in vivo AD pathologies, including cerebral Aβ deposition, neurodegeneration of AD-signature regions, and cerebral white matter hyperintensities (WMHs) in the living human brain. The present study was part of the Korean Brain Aging Study for Early Diagnosis and Prediction of Alzheimer’s Disease (KBASE), an ongoing prospective cohort study that started in 2014. As of November 2016, 414 community-dwelling individuals with neither dementia nor alcohol-related disorders (280 cognitively normal [CN] individuals and 134 individuals with mild cognitive impairment [MCI]) between 56 and 90 years of age (mean age 70.9 years ± standard deviation 7.8; male, n [%] = 180 [43.5]) were recruited from 4 sites (i.e., 2 university hospitals and 2 public centers for dementia prevention and management) around Seoul, South Korea. All the participants underwent comprehensive clinical assessments comprising lifetime and current histories of alcohol intake and multimodal brain imaging, including [¹¹C] Pittsburgh compound B positron emission tomography (PET), [¹⁸F] fluorodeoxyglucose (FDG) PET, and magnetic resonance imaging (MRI) scans. Lifetime and current alcohol intake were categorized as follows: no drinking, p = 0.004). In contrast, current alcohol intake was not associated with amyloid deposition. Additionally, alcohol intake was not related to neurodegeneration of AD-signature regions or cerebral WMH volume. The present study had some limitations in that it had a cross-sectional design and depended on retrospective recall for alcohol drinking history. In this study, we observed in middle- and old-aged individuals with neither dementia nor alcohol-related disorders that moderate lifetime alcohol intake was associated with lower cerebral Aβ deposition compared to a lifetime history of not drinking. Moderate lifetime alcohol intake may have a beneficial influence on AD by reducing pathological amyloid deposition rather than amyloid-independent neurodegeneration or cerebrovascular injury.

박지웅, et al. J Korean Neuropsychiatr Assoc. 2020 Nov;59(4):293-302. https://doi.org/10.4306/jknpa.2020.59.4.293

Precise assessment of health-related quality of life (HRQOL) with a reliable and valid measure is a prerequisite to the enhancement of HRQOL. This study examined the psychometric properties of the Korean version of the Medical Outcomes Study HIV Health Survey (K-MOS-HIV). The reliability and validity of the K-MOS-HIV were examined in a multicenter survey involving 201 outpatients with human immunodeficiency virus (HIV)/ acquired immunodeficiency syndrome (AIDS) from four teaching hospitals throughout Korea. Ceiling effects were observed in six subscales scores, particularly, for the role functioning (71.1%), social functioning (63.2%), and pain (48.8%) scores. The Cronbach’s α for the physical health summary and mental health summary were 0.90 and 0.94, respectively, and it ranged from 0.78 to 0.95 for the subscales. The results of the exploratory structural equation modeling supported the two-factor structure of the K-MOS-HIV (physical health summary and mental health summary). An examination of the mean square statistics values from the Rasch analysis showed that the information-weighted fit and outlier-sensitive fit statistics were within the acceptable ranges of 0.6–1.4 except for two items in the mental health summary. The convergent validity of the K-MOS-HIV was supported by its significant positive correlations with the World Health Organization Quality of Life-HIV-BREF subscale scores. Its known-group validity was proven with its ability to detect significant differences in several K-MOS-HIV subscale scores among participants with different sociodemographic and clinical characteristics. The K-MOS-HIV health survey appears to be a reliable and valid measure of HRQOL.